Asked if Mubarak would step down, an Egyptian official told Reuters: "Most probably."
The BBC also quoted the head of Mubarak's political party as saying that the president might go.
"I spoke to the new secretary general of the ruling National Democratic Party, Hossan Badrawi," a BBC reporter said. "He said: 'I hope the president is handing over his powers tonight'.
The head of the U.S. Central Intelligence Agency also said it was likely Mubarak would step down in the next few hours.
"There's a strong likelihood that Mubarak may step down this evening, which would be significant in terms of where the, hopefully, orderly transition in Egypt takes place," Leon Panetta told a congressional hearing in Washington.
Prime Minister Ahmed Shafiq also told the BBC that the 82-year-old strongman may step down.
The president has been buffeted by widespread protests against poverty, repression and corruption that broke out last month in an unprecedented display of frustration at his autocratic rule.
Hundreds of thousands of people have taken to the streets to demand that Mubarak quit and clashes between protesters and security forces have killed at least 300 people.
Mubarak has clung on to power, promising to step down in September, but that was not enough to end the uprising.
On Thursday afternoon, Egypt's military announced it was taking measures to preserve the nation and aspirations of the people after a meeting of the Higher Army Council.
The meeting of the Higher Army Council was headed by the defense minister and Mubarak was not present, according to television footage.
Pro-democracy protesters in the main focus of the opposition, Tahrir, or Liberation, Square, cheered as it seemed that Mubarak's removal was imminent.
Organizers were promising another major push on the streets on Friday when protesters said they plan to move on to the state radio and television building in "The Day of Martyrs" dedicated to the dead.
Washington has pressured Mubarak to speed up the pace of reform but has stopped short of demanding the resignation of the president of the country, which has a peace treaty with Israel and an army which receives about $1.3 billion in U.S. aid a year.
"The army is facing the choice between standing with Mubarak and perhaps being swept aside or going with the popular flow. I think they will give away Mubarak almost as a fig leaf. Possibly (Vice President Omar) Suleiman as well, although he is not as unpopular as Mubarak. There is an element of regime preservation going on here from the army elite," Julien Barnes-Dacey, a Middle East analyst at Control Risks in London, told Reuters.
(Reporting by Samia Nakhoul, Tom Perry, Dina Zayed, Marwa Awad, Andrew Hammond, Alexander Dziadosz, Yasmine Saleh, Sherine El Madany, Patrick Werr, Edmund Blair, Jonathan Wright and Alison Williams in Cairo, Erika Solomon and Martin Dokoupil in Dubai, Arshad Mohammed in Washington, David Stamp in London and Brian Rohan in Berlin; Writing by Alastair Macdonald and Peter Millership; Editing by Angus MacSwan)